Toronto Hydro to test world's first underwater energy storage system

Toronto Hydro has announced it will launch the world’s first-ever underwater energy storage system in Lake Ontario.

The utility has partnered with Hydrostor Inc., a company that specializes in innovative energy storage systems, for a two-year-pilot project intended to create a backup for the city’s electricity grid big enough to power approximately 350 homes.

"We're very excited to see this new technology in action,” said Toronto Hydro CEO Anthony Haines. “Toronto Hydro has been very busy exploring new ways to power our grid, and I think this is the most creative project we've been involved in so far. Supporting innovative solutions for Toronto's power needs will continue to be a focus for our organization."

The system works by taking electrical energy and converting it into compressed air so that it can be stored under water in large, balloon-like structures.

The storage facility will be located three kilometres off the southern tip of the Toronto Island and 55 metres under water.

When the city’s electricity grid needs power, crews will open a valve that lets the pressurized air out. The air is then converted back into electricity and fed into the grid.

“By us being located in the city, we can take surplus electricity instead of exporting it at a loss to the province, store that and bring it back the next day instead of building another gas plant,” said Hydrostor CEO Curtis Vanwallegham.

Vanwallegham said the process is almost more cost-effective because it does not require long transmission lines connecting remote gas plants to the city.

Canada’s Minister of Innovation, Science and Economic Development Navdeep Bains said the project will help solidify Ontario’s position as a world leader in renewable energy initiatives.

"The world's first underwater compressed air energy storage system, which we're celebrating today, is a great example of the global impact Ontario-based companies can make when they have the support and resources they need to become world-leading innovators,” Bains said. “We look forward to seeing the global reach of this innovative technology."

If the pilot project is successful, Vanwallegham said Hydrostor will look to expand its operations worldwide.

“We would look to other cities around the world, mines, micro-grids (and) island nations to build and do our small part in moving to a 100 per cent renewable grid,” he said.

In the long term, Vanwallegham said these kinds of project could help reduce the cost of electricity for consumers.

“The only reason we build facilities is because they’re … a lower-cost alternative to the status quo,” Vanwallegham said.

City engineers will be monitoring the effectiveness of the system over the next two years.